In general, washing machines remove dust and dirt from clothing by performing a mechanical operation using water and a detergent. In recent years, an increasing number of washing machines have been equipped with a drier function for drying wet laundry with the use of a mechanical operation and hot wind generated by a heater.
A typical washing machine includes a washing tub, which is rotatably installed in the typical washing machine and can contain water and laundry therein. The typical washing machine performs a washing operation on laundry contained in the washing tub by rotating the washing tub with the aid of a driving unit. The typical washing machine also includes a water supply unit which supplies water into the washing tub, and a drainage unit which drains water from the washing tub. A detergent supply unit, which supplies a detergent into the washing tub, is disposed on a water supply path of the water supply unit. The detergent supply unit includes a dispenser which is connected to the water supply path and a detergent box which is installed so as to be able to be inserted into or ejected from the dispenser. Therefore, in order to supply a powder detergent or a liquid detergent into the washing tub, the detergent box may be taken out from the dispenser, a powder detergent or a liquid detergent may be injected into the detergent box, and the detergent box may be put back in the disperser. Then, if the water supply unit begins to operate, the powder detergent or the liquid detergent contained in the detergent box may be supplied into the washing tub along with water that flows along the water supply path of the water supply unit.
Conventionally, however, users are required to put a liquid detergent into a detergent box whenever necessary for a washing operation, thereby causing inconvenience and reducing the convenience of the use of a washing machine.